Build your own radar system

How we missed this one is anybody’s guess, but one of the presentations at DEFCON last year covers a DIY radar build. [Michael Scarito] talks about the concepts behind radar, and then goes on to show that it’s not too hard or expensive to build a setup of your own. We’ve embedded his 45 minute talk after the break.

The two large pieces of hardware above should look familiar. They’re descendents of a favorite hacking project, the cantenna. The can-based long-range antenna is most popular with WiFi applications, but we’ve seen it used for Bluetooth as well and it’s not surprising to see it here. The rest is a lot of sensing hardware and enough math crammed into the coding to make your ears droop.

If you make it far enough (exactly 39 minutes into the talk) [Michael] shares some links for more information on the build. We think living vicariously is enough for us, but if you manage to build your own setup don’t forget to post a project log!

Oh yes! I own the 1947 ARRL handbook, and even a smaller ARRL handbook, blue.

One thing about the RADAR though, I think in the United States, even hobbyist builds are questionable in the legal sense, I am not sure though. For example, when you sample chips from microchip, it asks if you are going to use the chips in any RADAR or missile items, and you are prohibited from doing so, if my memory serves me correctly. Anyone has any ideas about this?

That question from Microchip and other mfrs is generally related to export control and arms trade regulations AFAIK.

They want to know you’re not going to build weapons or military hardware (i.e., hardware to be sold to an actual military group) with their stuff, because that opens them up to a lot of paperwork and potential liability.

I can’t think of any reason it would be illegal to build or own your own personal radar if you’re not using it on a prohibited weapon.

It might be illegal to operate that radar if you don’t have the proper radio license and/or transmit with too much power.

I’ve been thinking about this for a bit. I think a dynamic cruise control could be done much more simply than this general purpose radar. Get one of those toy store baseball speed guns and stash the bits behind the bumper, take the speed signal going to the display and feed it into an arduino set up as a PID controller to minimize the relative speed, with the output going to the existing cruise control.

The only problem would be to control the brakes in case they brake rapidly (e.g. deer or other animal in the road). Plus I wonder if it’d trigger one of those anti-radar sensors some people have installed, which cause people to freak out and slow down.